Does it need more seasoning? Another stock cube, pepper etc? I do think plenty of seasoning is important. And personally I don't think I'd semi-blitz - either wholly or not at all.
I make a lot of soups in autumn/winter, with whatever I have, but always inc. onion and celery for flavour. And usually potato. I chop all veg very small and often start off with sweated chopped onion and celery. . Those and chopped root veg (carrot, swede turnip, whatever), plus often a handful of pearl barley and/or red lentils, simmer in stock for a good half hour.
Any green veg (cabbage, quartered sprouts, chopped leeks, etc. go in just for the last 5 mins or so. I never blitz this sort of soup..
Sometimes I add some small pasta - e.g.orzo, the one that looks like rice - for the last 10 mins.
Usually served with plenty of grated cheese sprinkled on top. These are main-meal soups - dh would happily eat them just about every day!
Another one (easy!) that's been popular in winter is curried parsnip - sweat some chopped onion with curry powder, add chicken or veg stock and plenty of peeled parsnips in chunks, simmer until parsnips are very soft, and then blitz. Taste to check seasoning, adjust if necessary.