I guess it all stems for women fighting for equal rights, to go to work, be paid the same as men etc. That doesn't mean there shouldn't be a choice, more that we have the opportunity to do so, as with voting.
Huge steps were made so we can also have well paid careers and it's so sad so many bright women in the past weren't allowed this opportunity unless from a very wealthy background. It also means men had total control due to finances and their partners and many abused this position.
Now, things have changed a lot and with it there has been a transition in expectations for wives/girlfriends to have more power and responsibility for their own finances and work so as not be left vulnerable.
As with anything in society, it all depends on individual circumstances. If you're in a loving relationship and your partner happily supports his family and to be able to be a sahm is wonderful for everyone.
While working and the pride, forming relationships, making a difference in a lot of jobs that comes from it is one thing, I do believe many women would also love to be a sahm and so likely some of the comments you are getting are jealousy, concern you're not experiencing the full life available and worry about being totally dependant on DP.
So pros and cons but if you have the opportunity to be able to afford to be a sahm then it really is the best thing for your dc to be there for, having time to keep on top of maintenance a household and opportunity, if wanted, for much needed and rewarding voluntary work. Being a Mum and housewife is a combined job which can take up all of your time though of course and no you shouldn't feel guilty, ignore them, everyone needs to do what is best for themselves. Enjoy it! Xx