Pedro I of Brazil is not venerated neither hated in Brazil.
It roots in the sui generis history of independence of Brazil, and personally of his founder and liberator.
- Pedro I was born in Lisbon, Portugal, 1798.
- The Portuguese Court transferred to Rio de Janeiro in 1808, running away of Napoleon invasion of Iberian Peninsula.
- It created the sui generis situation of the capital of a Empire residing in one of its Colony, not in the Metropolis.
- His father, John VI, became King of the United Kingdom of Portugal, Brazil and the Algarves in 1816.
- In 1821, when it was safe to return, John VI went back to Lisbon.
- Pedro I declared independence in 1822.
- Portugal, ruled by his father, accepted independence in 1825. The whole process of independence was, with a few exceptions, pretty peaceful compared to the process of other countries in the continent.
- When his father died, in 1826, he also briefly reigned over Portugal, from 10 march to 2 may.
- He abdicated the Brazilian Crown in 1831 and went back to Portugal.
- He died on 1834, in Lisbon.
Therefore, despite being the de facto founder of the country, it is hard to view him as an "authentic liberator" (specially compared with the founders of the USA or Bolivar, José de San Martín, etc.), or even as an "authentic Brazilian".
In fact, despite being a national holiday, Brazilians celebrates its independence day (7 of september) way less than other countries on Americas.
Edit: it is not to say that there were not wishes of independence on Brazil. On the contrary, Brazil had separatist and republican movements since the eighteenth century. Another national holiday on April 21 celebrates Joaquim José da Silva Xavier, known as Tiradentes, executed as a leading member of the Minas Gerais Conspiracy, in 1792. Another national holiday celebrates the Proclamation of the Republic, which happened November 15 (1889). So, the ambiguous or little relevance of Dom Pedro I roots in some perception that his declaration of independence was a stratagem of the Portuguese Royal to not lose power. Usurping the authentic wishes of independence and specially of republicanism.