Manager Jackie McNamara preferred to focus on the positives after proved to be not enough for a possible European place.
"We are not disappointed, you get what you deserve," said the United boss after meant they finished fourth.
"It's one more victory than we had last year but it wasn't enough.
"For me, maybe that extra couple of weeks to settle the team in again and rebuild it (will be better)."
Nadir Ciftci's two goals gave United a 2-0 half-time lead and another after the break by Blair Spittal helped the Terrors round off their season with a satisfying win.
"We were a constant threat with our movement and possibly we could have had one or two more," McNamara told BBC Radio Scotland.
United finish the season on 56 points from 38 matches, one point fewer than Saints, their other Tayside rivals, who need third-place Inverness to beat Falkirk in the Scottish Cup final to clear a path for them into the Europa League qualifiers.
For McNamara, his task this summer is not to navigate the early rounds of European competition but to reshape the squad for next season, having lost Andrew Robertson,Ryan Gauld,Gary Mackay-Steven and Stuart Armstrong in the past 11 months, and hoping John Souttar and Ciftci sign the new deals on offer.
"I've been here for over two years and it's been rebuilding and rebuilding," said the former Partick Thistle boss.
"It's well documented, the debt, and having to work to a stringent budget.
"It's been difficult. We have lost four fantastic stars and not many teams can cope with that without spending a lot of money.
"I hope not (to lose others). The debt is about away so now it is about building and moving forward and keeping our players a lot longer."
"We look to the youth like young Spittal and (Robbie) Muirhead, who we took from Kilmarnock.
Dundee manager Paul Hartley described the defeat as "a difficult one".
"You always want to finish the season on a high, especially on a derby game," he said.
"I actually thought we played at times today, but we gave away some poor goals.
"It's something we have to look at for next season, getting more clean sheets, but overall I'm pleased with the players.
"We just didn't have the final pass or final shot, the cutting edge which United had.
"The first goal had three mistakes in it. They get one from a penalty - we have to be better in the box and stay on our feet - and the third was just a poor goal to lose."
Hartley, who has signed Kane Hemmings, Nicky Low, Rory Low, Daryll Meggatt and Kevin Holt for next season, added: "Getting in the top six has been great but next season is going to be much more difficult, with Hearts coming up, possibly Rangers, so we have to do much better.
"The squad will be younger, there will be more energy in the team and the competition for a place will be much stronger.
"I am delighted with the guys I've got in and we want to add one or two others.
"We've spoken to one or two others about offering contracts, we'll just need to wait on that one."