Tillers make a weed seed bank. The seeds you tilled in last year or the years before get brought up this year and sprout. Loots if grasses and plants like blackberry are going to thrive after getting cut up and spread around. The only thing to do now is hoe out the weeds every couple days this season.
Tillers also make a compacted area under the loose tilled soil, when it rains your garden turns into pond. Ammending a huge tilled area takes alot if ammendments. No reason to ammend the pathways. Raised beds, tarps, fire torch, woodchips, cover crops, roller crimpers might be stuff to look into for next season.
Good luck!
RE: Looking for advice to improve our garden soil!