OP, yanbu, absolutely not.
The situation of such entitlement means that it would be a complete disaster.
There are far too many people involved.
Of course you want it to be available for yourselves.
I have a second home as do several of my friends.
You need to be so careful about loaning it out.
My friend was initially generous the first year.
They had freshened the cottage up themselves and had made it very cosy, but she found when she would visit it was a bit grimey.
Multiple family had stayed but no one was leaving the house as they had found it, and she spent the first couple of hours cleaning so she could feel comfortable in her home.
The final incident was a bin with food left in it and the bathroom was grubby.
She sent a text to the family saying that unfortunately it wasn't working out and it was no longer available.
There was pushback but by this point she was so pissed off, she didn't care.
She bitterly regrets ever saying yes.
She is reasonably house proud and some people are rude enough think a quick wipe around is enough after a free holiday for a week.
There are too many people in your life wanting it, it will not end well.
Hold your position firmly.
Once you say yes to even one person, it will only cause even worse drama.
A blanket no is best.
I hear you about selfish parents.
You do not feel inclined to share something you have worked hard to fund with people that actually were quite selfish.
For me, finding a house that I left in ship shape, grimey from others, would spoil it.
As my friend said, she became a bit stressed before heading off as she wasn't sure what would greet her.
She also felt she had to clear it after each visit when she wanted to leave her bits there, making it easier to just head away.
Her family had years of fantastic exotic holidays for years, whilst they quietly saved the deposit for their little cottage.
It is extremely entitled to ask for something that was never offered.
Stay strong and see less of them.
They do not value you if they think making digs like that is on.
Don't tolerate it.