They’re the same kind of tab; not a completely different application. Should we also listen to music in Dolphin? Watching video in Dolphin? Edit files in Dolphin? Should we make Dolphin the only app on the system and do everything in it?
Typically, when I open a terminal I want a normal size one, so I can see file listings, scrolling data etc. In my case I would say 99 times out of 100 I want a regular terminal rather than a small one at the bottom.