I'm more likely to give someone a hard time for using email at all. I find it increasingly less useful every year. Currently it's a massive storage of confirmation emails and receipts for me.
Self-hosting has the added advantage of offering "unlimited" storage space, as many addresses using whatever creative schemes you want - I give specific addresses to all commercial/government/organisational institutions I communicate with which allows me to spot who abuses or leaks addresses and makes it possible to block those and only those addresses. SMTP and IMAP have their warts but they remain among the few well-specified open protocols which enable communication with anyone who can follow the standards. Any "successor" to these better be just as open, well-specified and preferably backwards-compatible with SMTP or it probably won't fly.