It's just bad application behavior imho.
On my MacBook with "only" 4GB 155MB counts. Let's be honest, we're talking about a password manager. That's a small database program with a low amount of data (records/fields).
Safe in Cloud, with the same number of items, has a database of 50Kb. In Enpass that's 1MB. Now diskspace isn't a problem, although why should a database be that much larger? That does count when syncing on a mobile over a 3G connection.
Why should I waste 155MB of memory when it could be done in, let's say, 30MB (like PWSafe)? Why waste memory?
Same reason why I uses Echofon (80MB after some time) instead of TweetBot (250MB after some time).
Sure in these days GB's are cheap. But with 4GB of memory (of which 1,5-2GB is actually usable space) it doesn't hurt to be careful.