To think hotels are very child unfriendly

you need to go to family friendly hotels

We don't do hotels anymore, unless they're specifically family friendly ones abroad, or occasionally a B&B/pub type thing, but mostly we do self-catering now. It suits the kids miles better in my opinion, and is more of a "relaxing" break as the kids can go to bed and we can stay up and we're not having to wait for breakfast (or rush and get everyone up for breakfast!) in the morning.

Just because there were other children in the hotel doesn't mean it's family friendly.

I call reverse

Hmmm, I think these are 3 bad examples tbh

1. The people reading newspapers are not the hotel. Different people have different reactions to kids being a bit disruptive in different situations. Plus, some people have a resting face that looks like a dirty look. I'm one of them - but it very rarely means I am thinking about anything other than being distracted with my own thoughts.
2. Most hotel rooms are built to keep noise contained - otherwise the hotel would be inundated with complaints abut TVs, hairdryers, etc. So, I'm guessing either you were in the kind of hotel that used to be something else (and so soundproofing was perhaps less than standard) - which is not great for kids tbh - or your children were actually a bit nosier than you thought - in order to be heard next door.
3. It's 1.5 hours out of (presumably) the whole day. Does not seem unreasonable to just keep the earlier day slot for adults only in the pool.

No one would call reception for one child's squeel. People don't leave comfy sofas for kids just running around a bit.
Pool, well depends if it was set on their website or not.
It doesn't sound like hotel aimed at families. There are PLENTY of those though

People don't go away to listen to other people's kids. You say they were letting off steam... they upset people enough to make them leave. They were then loud enough, early enough to upset people enough to ring reception and complain. And then you complain that you can't go interfere with an adults only swimming session. No words really.

I think you’re probably in the bit of having young dc where you don’t realise just how loud / disruptive they are.

The running around the lobby - no, I wouldn’t let my dc do that. Of course it’s going to annoy other people / potentially be dangerous.

How long had the dc been up playing by 7am? One of ours used to wake up v early and it was tricky keeping them quiet but you have to because objectively 7am is early to be woken on a weekend hotel break.

You’re right that hotels aren’t the most young child friendly. But I don’t think they have to be. Just choose better places to go away - we did lots of self catering cottages when dc were similar ages to yours. Easier all round. And know that if you are choosing a hotel, you will need to make sure your dc understand how to behave rather than the hotel needing to flex to them.

Find a family friendly hotel and do lots of research.

There’s loads of family friendly hotels.

Tbh we stay in various hotels. I think it’s fine. It’s never occurred to me to take Ds swimming at 7am. If he wakes early he gets some tv in hotel room in bed which is novelty. By the time everyone is up dressed and we go have breakfast it’s after 9am.

I wouldn’t ever let him run around in reception on checking in, dh or I would check in and the other sit with ds if needed or take him for stroll outside. He’s 3. Hotel rooms are generally fine to let them play in, the walls aren’t that paper thin for regular children playing noise.

I think children only swimming hours are standard and we always check. Often it's kids only allowed between 8-11 and e.g. 3-7.30pm. Which is fine.

I'd be annoyed about kids "letting off steam" in a reception area. Do it outside. Whilst everyone has different parenting styles and standards, unless it's a family friendly hotel or a cheapie like a premier Inn, I'd not be happy either.

Go to a family friendly hotel?

Tbh I think hotels are purposefully not kid friendly. The majority of people don’t want other people’s kids destroying their break. I’ve been woken up before and I was furious ( have 4 kids at home) when I’m resting without them I certainly don’t want anyone else’s kids ruining it. It’s harsh I know, but kids don’t buy hotel rooms, adults do. That’s the target market.

Is this a hotel which is marketed as family-friendly? Some hotels are more aimed at couples/business and some are aimed at families.. if you have a long drive I’d look for one that has a play area (often ones which are attached to pubs are close to play areas in the pub gardens)

I think family friendly hotels or self-catering hotels are your best bet OP.

I would not have let my kids squeal at 7am or run around a reception lobby. But I had easy kids.

Choose an explicitly family friendly hotel?