I had this exact same experience at a previous startup. It was really frustrating to me, it was so easy for new devs joining the team to criticize past work. It

I had this exact same experience at a previous startup. It was really frustrating to me, it was so easy for new devs joining the team to criticize past work. It was especially difficult for me because I'm not a natural leader and I tend to avoid conflict. On top of that, I already knew I was cutting corners, it's just impossible when I was the only developer and was forced to make tradeoffs and meet deadlines all the time. But the new team members weren't around for those times so they were blind to previous state. I'm now working for a different startup of very smart people and engineers and see that it's just normal to have all kinds of tech debt. My previous experience has given me valuable perspective, I don't complain about how/why things are the way they are I just do the best I can to improve it and ship features.