1)
How was there not like this from the days of Shlomo?
1.
'Rashi': Perhaps there were more people in the days of Shlomo, but the Simchah was greater now, for all the days of Achaz and the evil Malchei Yehudah, they could not ascend to Yerushalayim for the festival, and now they could. The seven days of Pesach did not suffice for their Simchah, so they added another seven. (Refer to 30:3:1:1 and the note there.)
2.
Malbim: In Shlomo's days, all of Yisrael were united in Yerushalayim. Afterwards, the 10 tribes did not ascend for the Regel, until now.
